JP2944272B2 - Cutting device for cutting looper thread in a multi-needle chain stitch sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cutting device of the type described in the preamble of claim 1, that is, a looper thread in a multi-needle chain stitch sewing machine (multi-needle chain stitch sewing machine) which is automatically controlled. A sewing device for guiding at least one needle thread on each of the left and right sides, a sewing material mounting table , a presser, a looper thread guide, and a looper thread. A looper with a hook portion for catching, a movable thread catcher with a knife edge used to catch the looper thread between the upper surface of the presser and the looper thread guide, a cutting knife, and a looper thread. And a type in which a thread clamp is provided.

[0002]

BACKGROUND OF THE INVENTION German Patent Application Publication No. 372 used to construct a device according to the preamble of claim 1
It is already known to catch looper thread between the looper and the upper surface of the presser and to guide it towards a combined catching and cutting device arranged in front of the looper, as disclosed in US Pat. It has become. If such a measure is taken, the obliquely forward looper thread which can securely engage the looper thread around the needle thread even when the needle thread starting end on the sewing material is short is used. Despite the guidance direction being obtained, the handling of the fabric during the sewing operation is impeded due to the constructional reasons that the combined catching and cutting device is arranged laterally and below the looper. .

[0003] Published German Patent Application No. 3531
A further known cutting device from U.S. Pat. No. 595 uses a cutting knife for cutting a looper thread with a hook edge, which is cut from the upper rear diagonal to the center of the looper thread. A mechanical forward and backward movement is performed between the looper and the sewing cloth. However, this device creates a long needle thread starting end that interferes with many sewing operations. Moreover, in order to provide a visually satisfactory final product, the thread ends must be additionally cut off after the sewing is completed.

[0004] The method of cutting off the remaining sutures at the seam ends belongs to the general category of known techniques and is disclosed in detail, for example, in DE-A 25 38 916.

[0005]

The problem to be solved by the present invention is to improve the conventional cutting device of the type described at the outset so that at the start of the sewing operation only short thread ends are obtained from the sewn material. An object of the present invention is to prevent the protrusion from protruding, and to prevent the handling of the fabric during the work by the worker.

[0006]

According to the measure of the invention proposed to solve the above-mentioned problem, that is to say the measure described in its characterizing concept in claim 1, the yarn catcher has a rear lower inactive. From the position behind the looper towards the upper upper catching position above the looper and from there back again to the inoperative position, cooperating with the drive and the guide, and furthermore the thread catcher During the movement, the looper thread extending between the hook portion of the looper and the looper thread guide is captured toward the inoperative position, and the thread clamp disposed in the range of the sewing needle on the left side and the thread clamp at an ambassador distance. It is configured to be forcibly guided toward a cutting knife assigned to the clamp.

[0007]

If the above measures are taken, the fabric can be handled without any trouble during the sewing operation even if the starting end of the needle thread is short.

The objects described in claims 2 to 5 relate to expedient and advantageous embodiments in the configuration of claim 1.

If the thread catcher, which is constructed as a double leg as described in claim 2, is pivotally connected to the thrust rod as in claim 3, a particularly simple and cost-effective structure is provided. Is obtained.

According to a preferred embodiment of the invention, a pneumatic cylinder is used as a drive for the simple operation of the thread catcher pivotally mounted between the cutting knife and the thread clamp. Used.

According to claim 5, the free end of the spring configured as a leaf spring acts on the cutting knife. in this case,
The cutting pressure between the cutting knife and the thread catcher is adjustable by means of screws.

According to the configuration described in claim 6, the tightening pressure between the yarn clamp and the yarn catcher can be adjusted, so that the supplementary pressure corresponding to the type of the looper yarn used each time is adjusted. It is possible to optimize the tightening pressure.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to the embodiment shown in the accompanying drawings, in which: FIG. 1 shows the arrangement of a cutting device in a multi-needle chain stitch machine, its main components; The holder (4) of the cutting device is fixed to the casing (1) by screws (2) and (3).
The drive, which is designed as a pneumatic cylinder (6), is fixed to a holder (4) by means of a screw (5), and this cylinder (6) has two compressed air lines (7), (8).
The pressurized air is supplied alternately via.

The piston rod (9) is provided with a hinge (11) used as a receiving portion for a reciprocating thrust rod (12).
Is the leg (1) of the movablely supported thread catcher (15).
4) is pivotally connected via a fork head (13).

The sewing cloth (19) is mounted on the sewing cloth mounting table (1).
6) and the upper surface (18) of the presser (17). Needle heads (22) which respectively receive at least one left-hand sewing needle (23) and one right-hand sewing needle (24) can move up and down.
And the needle threads (25), (26) are guided by these sewing needles.

The needle head (2) viewed from the plane of FIG.
On the right side of 2), a slitted looper thread guide (27) and a driven looper (28) are arranged, and the looper (28) is used to catch the looper thread (30). A hook part (29) is provided.

The looper thread (30) is passed through a looped thread loop guide (27) through a ring (32) of a needle head (22) while being controlled by a thread brake (31). (28) is guided toward the hook portion (29), from which the sewing cloth (1)
You will be guided to 9).

FIG. 2 shows a holding rod (33) which is vertically movable within the casing (1). The holding rod (33) is provided with a holding member (17) by a screw (34). Fixed. Guide plate (37) is screwed (3
5), a cutting knife (40) fixed to the free end of the holder (4) via (36) and the guide plate (37) itself fixed by two screws (38), (39). Is carried. The thread catcher (15) is pivotally guided by a guide part including a cutting knife (40), a guide bolt (41) and a guide plate (37), and is pivotably supported. The thread catcher (15) occupies a rear lower inactive position (42) provided above the upper surface (18) of the presser (17) and behind the looper (28), and the looper (28) It has a notch (43) which is used as a movement trajectory (44) in the catcher (15). Thread catcher (15)
Is the motion trajectory (44) of the looper (28).
Intersect with 5).

In the embodiment shown in FIG. 3, the cutting device used for cutting the looper thread (30) is located above the looper (28) in the upper upper catching position (4).
7) has a thread catcher (15) configured as a double leg (46). This thread catcher (15) has a knife edge (48) arranged stepped with respect to the arc-shaped catcher edge (49), and occupies the left end position (50) in the drawing plane. ing. The free end of the guide plate (37) is configured as a thread clamp (51).

FIG. 4 shows the tightening and cutting positions of the thread catcher (15) corresponding to the inoperative position (42), in which case the looper thread (30) is connected to the looper thread guide (27). The tip (5) of the sewing needle (24) which is passed through the slit (52) formed and is located on the right side.
At a distance (55) shown in FIGS. 5 and 6 until the thread clamp (51) is reached short of the point (54) of the sewing needle (23) located behind and on the left side in 3). It extends until it reaches a stationary cutting knife (40) located on this thread clamp (51).

FIG. 5 shows the individual parts of the cutting device for cutting the looper thread (30) in an exploded state. Cylinder chamber (56) of pneumatic cylinder (6)
In the piston (5) having a piston rod (9)
7) is reciprocally supported. In this case, it is possible to control the switching of the piston (57) of a known type by using a control unit (not shown), whereby the opening and catching movement of the thread catcher (15) can be adjusted. The piston rod (9) carries a spherical receiving portion (58) at the lower end thereof, and the spherical receiving portion (5).
A hollow sphere (59) fixed to the thrust rod (12) is supported inside 8), and is pivotally secured via a hollow flange nut (60) forming a hinge (11). Fork head (13) is thread catcher (1
5) It has one pin (61) fitted into the perforated part (62) provided in the leg part (14), and has a pneumatic cylinder (13) through a thrust rod (12). 6).

The guide bolt (41) is passed through a perforated portion (63) provided in the thread catcher (15) to guide the thread catcher (15) and adjust the tightening and cutting pressure of the cutting device. Secured by the lock nut (64) used. The holder (4) is adjustably fixed to the casing (1) via two slots (65), (66).

FIG. 6 shows the individual parts of a cutting device according to another embodiment in an exploded state, and the clamping pressure and the cutting pressure of the cutting device can be adjusted separately. In this embodiment, components having the same structure or function as those shown in FIG. 5 are denoted by the same reference numerals. In this case, beside the cutting knife (40), an additional spring (67) acting on this knife is provided, which spring (67), which is designed to function as a leaf spring (68), It is fastened and fixed to the cutting knife (40) by screws (38), (39). Between the guide plate (69) and the cutting knife (40), intermediate members (38), (39) which are fixed to the guide plate (69) together with the leaf spring (68) and the cutting knife (40) by screws (38), (39). 71) are arranged at a distance (55). Behind the guide plate (69) designed to be shorter than the guide plate (37), the thread clamp (7)
2) is formed, this thread clamp (72) produces a clamping pressure which is adjustable relative to the thread catcher (15) and between the guide plate (69) and the holder (4). It functions as a leaf spring (73) to be arranged. The flat nut (75) supported in the perforated portion (74) of the guide plate (69) is secured so as not to rotate relatively due to the stepped leaf spring (73). The cutting pressure generated between the cutting knife (40) and the knife edge (48) of the thread catcher (15) is a flat nut (75).
It can be adjusted by pivoting a guide bolt (41), which is operatively engaged therein, and tightens between the thread clamp (72) and the catcher edge (49) of the thread catcher (15). The urging force can be adjusted by a lock nut (64).

After the sewing operation is completed, a positioning drive (not shown) brings the needle bar (21) to the thread cutting position, ie, the needle lifting position, and the looper drive moves the looper (28) to the left end position. Move to (50).
In this looper position, the looper thread (30) is
Is guided around the hook portion (29) in a mountain shape. Since the thread clamps (51) to (72) are arranged in the range of the sewing needle (23) located on the left side, the cloth (9) in which only the end of the short looper thread (30) is sewn after the thread is cut. ), And at the same time
It is also possible to prevent the operator from handling the sewing cloth (9) during the sewing operation.

The cutting device, which is closed during the sewing operation and occupies the inoperative position (42), is connected to the cylinder chamber (5) from the pressurized air line (8) as a tube during the cutting process.
6) Pressurized air is supplied into the thrust rod (12).
Is released by being lifted. in this case,
The drive unit and the guide unit are arranged so that the thread catcher (15) is moved from the rear lower inoperative position (42) behind the looper (28) to the front upper upper catching position (47) above the looper (28). Work together. During this opening movement, the curved green portion (76) of the thread catcher (15) forcibly guides the looper thread (30) toward the looper (28). During the catching or closing movement in which the thread catcher (15) moves from the catching position (47) towards the inoperative position (42), the arc-shaped catcher edge (49) of the thread catcher (15) causes the looper (49). The looper thread (30) extending between the hook part (29) of the looper (28) and the looper thread guide (27) is captured, and this thread is disposed in the range of the sewing needle (23) located on the left side. Pull or push (forced guidance) towards the thread clamps (51) to (72). Due to the fact that the cutting edge is offset relative to the catcher edge, the looper thread (30) is first clamped between the thread clamps (51) to (72) and the thread catcher (15). Is then cut by the knife edge (48) of the thread catcher in the cutting knife (40). Thus, a tight looper thread (30) can be obtained in the immediate vicinity of the sewing needle (23) located on the left side as shown in FIG.

When starting to sew another fabric (19) to be sewn, as long as a new stitch is not formed, in other words, when forming a new stitch, the looper thread (3) is formed.
The looper thread (30) is not released from the thread clamps (51), (72) unless it is guaranteed that the 0) will be securely engaged around the needle thread (25), (26).

[Brief description of the drawings]

FIG. 1 is a front view of a cutting device for cutting a looper thread in a multi-needle and chain stitch sewing machine.

FIG. 2 is a perspective view of the cutting device in which a thread catcher occupies an inoperative position, as viewed from the left side.

FIG. 3 is a perspective view from the left side of the cutting device in which the yarn catcher occupies a capturing position.

FIG. 4 is a perspective view from the right side of the cutting device in which the thread catcher occupies a tightening and cutting position.

FIG. 5 is an exploded view of a cutting device according to one embodiment of the present invention.

FIG. 6 is an exploded view of a cutting device according to another embodiment of the present invention.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-55286 (JP, A) JP-A-61-276597 (JP, A) JP-A-64-70098 (JP, A) JP-A 52-1982 31153 (JP, A) JP-A 58-14871 (JP, U) JP-B 61-9080 (JP, B2) JP-B 63-10147 (JP, Y2) (58) Fields investigated (Int. Cl. ⁶ , DB name) D05B 63/00-65/06 D05B 57/02

Claims (6)

(57) [Claims] 1. A cutting device for automatically controlling the cutting of a looper thread in a multi-needle and chain stitch sewing machine, wherein at least one sewing needle is provided on each of right and left sides for guiding one needle thread. A sewing machine, a presser, a looper thread guide, a looper having a hook portion for catching the looper thread, and a looper thread used to catch the looper thread between the upper surface of the presser and the looper thread guide. In the form of a movable thread catcher with a knife edge, a cutting knife and a thread clamp for clamping and fixing the looper thread, the thread catcher (15) is in the rear lower inactive position. From (42) behind the looper (28), the looper (2)
8) Towards the upper front upper capturing position (47)
The drive (cylinder 6, thrust rod 12) so as to be able to move and then back again to the inoperative position (42)
And cooperates with the guides (cutting knife 40, guide bolts 41, guide plates 37 to 69), and furthermore, this thread catcher (15) moves the looper (28) towards the inoperative position (42) during the thread catching movement. The looper thread (3) extending between the hook portion (29) and the looper thread guide (27)
0) and a cutting knife (40) arranged in the region of the sewing needle (23) on the left and a cutting knife (40) assigned to the thread clamp (51, 72) at a distance (55). And a cutting device configured to be forcibly guided toward the cutting device. 2. The thread catcher (15) is configured as a double leg (46) pivotally supported between a cutting knife (40) and a thread clamp (51, 72). The cutting device according to claim 1, wherein 3. The leg (14) of the thread catcher (15).
3. The cutting device according to claim 2, wherein the cutting device is pivotally connected to a reciprocating thrust rod. 4. A reciprocating thrust rod (12).
4. The cutting device according to claim 3, wherein the cutting device is drivable via a pneumatic cylinder. 5. A spring (6) acting on a cutting knife (40).
7. The cutting device according to claim 1, wherein the leaf spring (68) is arranged beside the cutting knife (40). 6. The thread clamp according to claim 1, wherein the thread clamp is configured as a leaf spring having a clamping pressure which is adjustable relative to the thread catcher. The cutting device according to any one of Items 1 to 5.